Sugarcane Syrup Fermentation Challenges & Solutions – The Catalysts Group

Sugarcane Syrup Fermentation Challenges & Solutions

Fastest growing world is facing a serious energy crisis due to heavy dependency on petroleum fossil fuels, which is now going to exhaust rapidly because of day-to-day increase in the demand and also causing severe impact on the environment via emissions of greenhouse gases resulting in global warming by increasing the CO2 in the environment after burning of these petroleum fossil fuels.

Bioethanol, now a day comes as an alternative & eye catching option to address the fossil fuel exhaustion & global warming issues. Bioethanol is not only a renewable energy source but it is also seeming to be a sustainable solution because of many beneficial properties, such as:

  • Higher octane number
  • Fuel energy
  • Evaporation enthalpy
  • Flame speed with wider range of flammability
  • Higher compression ratio (CR)
  • Shorter burning time
  • Comparative enhanced efficiency over gasoline
  • 35% oxygen containing oxygenated fuel
  • Lower particulate & NOX emission
  • Lower GHG’s emission
  • Environment friendly

Bioethanol production is a well-known & well-established process, which includes the fermentation step i.e., conversion of simple sugar into ethanol through microorganisms; mainly yeast, followed by the distillation & rehydration steps. Many potential sugar-rich sources like sugarcane, sweet sorghum, sugar beet, grains, lignocelluloses, etc., generally used as a feedstock for different grades of ethanol production such as Potable, Pharma & Fuel grades. Production of ethanol from lignocellulosic/starchy feedstocks are comparatively less cost effective & more time-consuming process than from sugarcane juice, syrup & molasses, due to additional steps of starch pre-treatment to convert starch into simple sugars.

Indian government is aggressively promoting the bioethanol production in term to achieve the ethanol-petrol blending targets in shortest time period alongside to address the environmental pollution concerns too. Ethanol production from Cane Molasses is already in-place from last many decades, while the usage of Cane Juice/Syrup is very new for Indian distillers’ due to the un-known process challenges & highly perishable property of Juice/Syrup comparative to Molasses.

Sugarcane syrup fermentation is completely different from molasses ethanol production due to its unique properties, which includes; high brix, high sucrose concentration and very limited media buffer capacity. These properties often create undesirable osmotic stress on the yeast cell along with the drastic drop in pH at very low volatile acid production by bacterial contamination during fermentation. To maintain the enhanced fermentation efficiency, maximum ethanol yield and healthy yeast productivity, it is utmost necessary to control the undesired bacterial contamination, osmotic pressure reduction on yeast cell and excessive assimilable sugar supply for efficient attenuation rate during entire fermentation process.

Major challenges during syrup fermentation are as follows:

  • Sulphur stress specially “Sulphites” both in either single step sulphited syrup (Un-Sulphited Syrup) or dual step sulphited syrup (Sulphited Syrup)
  • Fastest growth of bacterial contamination including lactobacillus too
  • Lower buffer capacity of syrup
  • Lower volatile acid production initiates quick pH drops during fermentation which create ionic stress on yeast
  • Lower ethanol yield
  • Drop in fermentation efficiency
  • Osmotic stress on yeast
  • Viability & productivity challenges of yeast
  • Undesired by-products formation
  • Lengthier fermentation process
  • Higher residual sugar at end of fermentation

To address such process challenges during fermentation, Catalysts Biotechnologies has done very deep research & vast application studies on Syrup fermentation and observed a requirement of complete fermentation optimisation package. This fermentation product package has been developed for efficient & cost-economic syrup fermentation and to ease the distillers to run their syrup fermentation process without any hassles.

Syrup Fermentation Package includes the following products:

  • Catalysts ADY: A high alcohol tolerance, osmotic stress tolerance & highly suitable yeast to obtain high gravity ethanol fermentation using cane juice syrup as a feedstock.
  • DSPN- M: A nutritional strategy for yeast to enhance the ability of handling the variety of chemical stresses and to increase the metabolic process during reproduction and fermentation both. It also helps to provide the all desired vital nutrients for maximum productivity & health maintenance of yeast during entire process.
  • Bactoferm: An efficient product to control the undesirable lactic acid producing bacterial contamination such as lactobacillus, leuconostoc, etc. Lactic acid production during propagation and/or fermentation not only causes the loss of sugar due to bacterial consumption but it also creates the metabolic stress on yeast cell resulting in the lower ethanol yield and sometimes ceases the fermentation in mid.
  • Enzysyrup Max: A best suitable fermentation enzyme specially developed for the syrup fermentation for improved attenuation rate and to enhance the ethanol yield via maximum sugar availability from complex carbohydrates to yeast through enzymatic hydrolysis.

Bactosafe DF: A well-designed product having advance level of Biocidal activity against bacterial contamination, those comes from water/waste-water recycling streams. This product covers the broad-spectrum bacterial contaminations, which can come from any source like, condensate, spent lees, spent-wash, process water, environmental/surrounding environments, etc. This product is necessary to add in the process because of the mandatory requirement of spent wash recycling to maintain then solids in fermentation broth & MEE inlet feed both.